Engine control device



Aug. 15, 1944- c. H. JORGENSEN ETAL ,ENGINE CONTROL DEVICE OriginalFiled Sept. 25, 1957 3 Sheets-Sheet 3 :llllk 0 a m m my m in 3 HM E m mmer w a 4 [L 6 8 z a 2 2 0 72 6 3 3 w 2 W 3 0 F c /\7 n m 7 a 3 Z R 0 Z.

g g j, 3 Z 0 w j w W M In M JWATTORNEYS Patented Aug. 15, 1944 ENGINEcommon nnvros Clarence H. Iorgensen and Lawrence C. Dermond,

Anderson, Ind., assignors to GeneralMotors Corporation, Detroit, Mich.,a corporation of Delaware Original application September 23, 1937,Serial No. 165,326. Divided and this application May 16, 1944, SerialNo. 535,819

16 Claims.

This invention relates to mechanism for controlling the operation ofstarting devices for internal combustion engines, particularlythose ofautomotive vehicles. I

Semi automatic devices for controlling the operation of the startingmotor have been provided which have been so constructed that thestarting motor is caused to operate in response to actuation of one ofthe control members which must be manipulated by the operator of thevehicle to, control the operation of the engine as, for instance, theaccelerator pedal, but which are also controlled by engine suction insuch a way as to render the starting motor inoperative when the engineoperates under its own power. Devices of this kind have been providedwith a control switch operable in response to variations in enginesuction which is so constructed as to be opened by suction as soon asthe engine becomes self operative in order to break the circuit of thestarting motor and thus render said motor inoperative.

In the past, difllculty has been encountered in designing a controlswitch of this character which would be held open at all times that theengine is operating under its own power, but

which would not be opened by the suction thereon which is efiectiveduring the cranking" of the engine by the starting motor in order tostart the engine.-

It is the principal object of the present invention to provide a startercontrol apparatus of the character referred to which employs a controlswitch provided with means to prevent any possible opening of the switchduring operation of the engine by the starting motor but which willenable the switch tobe automatically maintained open during operation ofthe engine under its own power.

This application is a division of applicants copendlng application S. N.165,326 filed Sept. 23; 1937.

Further objects and invention will be apparent fromthe followingdescription, reference being had to the accompanying drawings wherein apreferred embodiment of the present invention is clearly shown.

In the drawings: I

Fig. 1 is a side elevation of a dual carburetor in which the automaticmechanism for controlling the action of the choke valve and the enginestarter is embodied.

Fig. 2 is a'sectlon along the line 2-2 of Fig. 1 with certain partsshown in elevation.

Fig. 8 is a horizontal section on the line 3-4 of Fig. 2 with certainparts shown in elevation,

Fig. 4 is a detailed sectional view on the line 4-4 of Fig. 8-

Fig. 5 is a diagrammatic section partly in elevation o! the whole unit.

Fig. 6 is a detailed sectional view of the switch-. operating mechanismshowing the parts in the position occupied while the engine is beingstarted.

Fig. 7 is a diagrammatic view of the circuit of the starter controlledsystem.

Referring primarily to Figs. 1 and 5, the reference numeral l0 indicatesthe carburetor in its entirety, such carburetor being provided with twoadvantages of the present valves 16 and II respectively, carried by acommon shaft 20, while the number 22 indicates a fuel chamber ofconventional type which partly surrounds the intake passages andsupplies fuel thereto in any desirable way. The carburetor is of thedown-draft type and is attached when in use to the intake manifoldindicated at 24, while adjacent the manifold and case integral therewithis a chamber 26 through which exhaust gas passes. This may be theexhaust manifold itself,

or may be a chamber connected for use combining what is known in the artas a hot spot."

This chamber supplies the heat that is utilized to heat the thermostatwhich regulates the choke valve in a manner hereinafter more fullydescribed.

An operating connection for the throttle shaft of a conventional type isprovided which is not shown' and a connection ll extends from thethrottle shaft to an accelerator pump, this mechanism being no part ofthe present invention.

An unbalanced valve 32 is positioned in the air inlet I4 and the valve32 is secured of! center on a shaft 36 which is Journaled for rotationin the walls of the air inlet 34 and is operable by the pressure of theincoming air. This valve obviousiy regulates the admission of air to thecarburetor and the air flowing past such valve is mixed with fuel toform the mixture which is supplied by the passages l2 and M to theengine.

The shaft it to which the unbalanced valve is secured is adapted to beoperated by mechanism a recess 44 formed in one end of shaft and iskeyed thereto. The other end of the flexible cable projects into asimilar recess 46 formed in the upper end of a shaft 40 which isjournaled in a sleeve 50 received in the housing 00 as indicated inFig. 1. The shaft 40 is suitably journaled for rotation and alsojournaled for rotation on the sleeve in a manner which does notconstitute a part of this invention and. is not shown herein, is asegmental gear I2, by means of which the suction operated mechanism isadapted to rotate the shaft 48, such suction operating mechanismoperating through the medium of the thermostat as will be now described.

Depending from the segmental gear is a pin 44 which is suitably securedto the segmental gear and engages in a slot 50 formed in a bifurcatedmember 58, best shown in Fig. 5, which is secured by rivets, or in anyother desirable way, to a thermostat 60 which is preferably in the formof a spiral coil that surrounds the lower end of the shaft 48 and hasits lower end secured to the bottom of the shaft, the thermostatextending longitudinally of the shaft from the gear segment to the lowerend of said shaft.

The means for securing the thermostat to the lower end of the shaft 40is capable of adjustment in order to vary the force exerted by thethermostat on the shaft 40 for any given temperature when thetemperature is low. This means includes a member or bracket 62 to whichthe lower end of the thermostat is riveted, as indicated in Fig. 2. Aportion of the bracket is U-shaped in form, the lower arm of the Uindicated by reference numeral 64 having an orifice therein throughwhich the lower end of the shaft 48 passes, while the upper arm 08 ofthe U-shaped member is bifurcated and receives the shaft between the twoforks thereof. The vertical portion 68 of the U-shaped member isprovided with an orifice in which a set, screw is threaded so that theend of the screw engages the reduced portion I2 of the shaft 48 and maybe tightened to secure the member 66 in any desired position withrespect to the-shaft.

The gear segment 52 is provided with teeth '14 which engage teeth I6formed on the exterior surface of the piston member I8 received within acylinder 80 formed within the housing 08 and the piston is normallyadapted to be held in the position shown in Fig. 5 by a spring 82, whichis received in the cylinder between the end thereof and the piston whichis partially hollow to embrace the spring. The piston slides within thecylinder due to the suction of the engine and under the influence ofother forces as will be more particularly set forth hereinafter, butwhen it is held in any given position by the spring 82, or by any othermeans, a change in temperature will cause expansion or contraction ofthe thermostat and if the piston be stationary at this time, the gearsegment 52 is held stationary so that this expansion or contraction ofthe thermostat will cause the free end thereof to move and to so rotatethe shaft 40 which. through the flexible connection 42 previouslydescribed. will move the valve toward open or closed position, expansionof the thermostat due to a rise in temperature causing the valve to openand contraction of the thermostat having the reverse effect and causingthe valve to close.

The suction-operated piston hereinafter referred to, under normalconditions when the engine is not running, is held in position at theleft of the cylinder in which it slides by the spring 82. As soon as theengine starts to rotate when it is being turned by the starting motorduring the cranking period and before the engine starts to run under itsown power, suction is communicated to the cylinder in which the pistonslides through the passage 04 which connects with a sump or chamber 00,indicated In dotted lines in Fig. 2, formed within the housing 00 andthis in turn connects with a passage 00 also indicated in dotted linesin Fig. 2, which communicates with the carburetor intake passage Justposterior to the throttle valves I0 and I0. Through this series ofpassages the manimold vacuum is communicated to the cylinder 00 to theright of the piston II, as shown in Fig. 2, and any increase in suchvacuum tends to move the piston to the right, while a decrease in vacuumtends to cause movement of the piston to the left.

The piston I0 is provided with a hollow extension 00 into which projectsa rod 02 which extends through a closure member 04 secured in positionat the end of the extension 00 in any suitable manner. The rod 02 has anenlarged head 06 secured thereto in any desirable manner, which slideswithin the extension 00 and has a loose it therein, while at itsopposite end such rod is screwed into or otherwise secured to a solidpiston 00 which is slidable within a cylinder I00 formed in the housing00 directly opposite the cylinder 00. The gear teeth I6 hereinbeforereferred to, are formed on the outer surface of the extension 00 of thehollow piston 00.

The rod 02 has formed thereon integrally or secured thereto in anysuitable manner, a flange I02 which projects from the rod and betweenthe piston is received the upper end I04 01' a spring arm I06, the lowerend of which is coiled around a stud I00 secured in the wall by the armII! provided with an ear IIJ which extends around the spring. Theposition of arm H2 is controlled by another spring II 6 which ts coiledaround the stud I 08 and has end IIl engaging the carburetor housingWhirl its other end I20 engages an end I22 projecting from an arm I24,which is connected by a yoke piece with arm II2, the two arms and yokeforming an integral structure rotatable on the stud I00. The pressure ofthe spring end II 0 against the housing 00 reacts against end I22through the other end I20 of the spring to hold the parts in theposition shown, unless moved by means later described which will movethe arm H2 in a clockwise dlrection, and will put tension on spring armI04 to cause it to follow arm II2, as later described.

The cylinder I00 in which the piston slides is provided with a resilientclosure member I20 and the cylinder I00 and piston 98 constitute a mentof the piston I0 and in this manner insures that the choke is not movedto its different positions too rapidly, the operation of these partsbeing more fully described later.

Attention is invited particularly to bhe fact that in the wall of thecylinder I00 there is provided a tapered slot I28 which regulates theresistance of the above described dash pot to the motion of the partscontrolled thereby so that the dash pots resistance is less the furtherthe piston 88 is moved to the right. In other words, the dash pot doesnot provide as great a resistance to movement of the parts as the chokevalve approaches more open position and consequently the delay in itsmovement toward open position is reduced as the valve is openedprogressively.

Cooperating with the mechanism just described to determine the positionof rod 82 through the medium of the spring I04 is a cam I30, best shownin Fig. 2. This cam engages the roller I32 rotatably mounted on the endof the arm I24 and the cam is secured in any desirable manner to theshaft on which the throttles I8 and I8 are mounted. The arrangement issuch that as the throttles are moved toward their open positions the camis rotated counterclockwise and through its engagement with the rollerI32 the arm I24 is moved clockwise. The action of this arm and arm H2 issuch as to move arm II2 out of the way of spring ar-m I04 so that springarm I04 at its upper end can move to the right. At pressure of thespring arm I04 on the flange I02 is increased so that it will movepiston 18 to the right as later described and the tension of the springI I8 is increased to restore the parts to normal when the cam is movedback to its original position. It will be obvious that a reverse motionor the throttle shaft would permit the roller I32 to move upwardly andcause the upper end of the spring I04 and other parts to be moved totheleft by spring I I8. At the same time the end oi spring arm I04through its engagement with piston 88, moves the rod 82 and piston 18 tothe left. to effect a closing movement of the choke valve the movementof the piston 18 by rod 82 is brought about by engagement of flange I02with the projecting portion 80 of the piston 18. The actual movementswhich the rod 82 makes under various operating conditions will behereinafter more fully described.

It will be noted that the cam has a relatively steep portion Ia which iseffective to move the arm I24 downwardly very considerably during thefirst part of the opening movement of the throttle and an almostconcentric portion I301: which engages the roller I82 during the latterpart of the throttle opening for reasons which will be later set forth.The construction is such that almost all the movement of arm I24 iseifected during the first 40 degrees of throttle opening.

The gear segment 52 hereinbefore referred to and which is moved by thesuction operated piston is limited in its movement in either directiondepending upon the character of the mixture which is desired, so thatthe mixture which is formed by the carburetor can be varied in fuelratio by means of this limiting oi. movement of the gear segment.v Inorder that this movement or the gear segment may be variably limited forchanges of temperature, variation of fuel volatility, or for any otherreason that may be found desirable, the segment has two stops I40 andI42 (see Fig. 3) formed thereon which are adapted to engage with aneccentric member l44 carried by a pin I48 which extends through anopening in the housing 88 and is provided at its outer end with a knobI48 while between the knob and the wall of the housing is a springwasher I80 which presses against the wall of said housing when the thesame time the nut is tight engaging orifices I82 formed in the 18 wallof the housing which act as detents to hold the eccentric member I44 inany desired position of adjustment. The knob may be turned and theeccentric member rotated so as to variably limit the movement of the twostops I48 and I42 as such stops are rotated upon lateral movement of thepiston 18. By variably positioning the eccentric member the degree ofpressure of the thermostat on the choke valve to hold the latter open orclosed would be varied and this would vary the amount of air admittedfor any given suction eflect on the valve and so to this extent variablycontrols the mixture proportions for any setting of the eccentric memberI44 and this setting of said eccentric member controls the richness ofboth cranking V and running mixture.

It will be 'noted that the flexible cable 42 through which the movement0! the automatic control unit is transmitted to the choke valve, issurrounded by a rubber housing I for protection and to prevent dirt andthe like from getting on the flexible cable.

Heat is communicated to the thermostat to bring the thermostat up to ortoward engine temperature through a heater tube I62. This lower end oithe tube fits within a recess I84 formed in a boss I88 on the wall ofthe exhaust manifold 28 or on the hot spot as is found most desirable.The heater tube extends upwardly from the recess and surrounds aconsiderable portion of the thermostat forming an efllcient means forconducting heat hereto as the engine temperature rises. The heater tubemay be a single tube, or it may be surrounded with an outer tube I83which flts outside of this heater tube and if used would serve a doublepurpose; first, to give the heater tube some more air and thus increasethe efllciency and second, to protect the heater tube covering, dirt,water, etc. from entering the housing and from contact with thethermostat.

The preceding portion of this specification relates to the constructionof the control unit which operates the choke valve to regulate themixture proportions. According to the present invention there isembodied in this same control unit a switch which controls the action ofthe engine starter and the operation of which is controlled by theposition or the throttle valve. This switch mechanism is positionedwithin a housing indicated in its entirety by the reference numeral I10and which is adapted to be secured at the right hand end of the cylinder88 as shown best in Fig. 2. The housing is provided with proiecting earsI12 and I14 which are secured by machine screws I18 to the wall of themain unit housing 88 a gasket I18 being provided to form a tight Jointbetween the main housing and the supplemental switch housing I10. Theswitch comprises two contnts I80 and I82, contact I88 being supported bya spring arm I84 which is bent at right angles as indicated in Fig. 5and is secured to the housing I10 by rivets I88 but insulated therefromby washers I88 of insulating material. The contact I82 is supported by acontact arm I88 of relatively rigid material which is bent at rightangles and that portion of such arm most distant from the contact isseparated from the housing I10 by a washer of insulating material I82and is secured in the housing by rivets I84, or in any other desirableway. Binding posts. I88 and I88 are provided, to which the wires leadingfrom the starter control circuit to the switch formed by the contactsI80 and I82 were connected. This circuit will be more fully describedhereinafter.

- I" that A spring 2 is received between the spring arm I and a screw202 threaded in thehousing I'll. This spring tends to move the springarm I in a direction to close the contacts I" and I02 and by removal ofthe screw 202, springs of different strength or length can besubstituted to adjust the pressure exerted on the contact carrying armI.

The operating means which control the opening and closing of thecontacts ill and "2 in clude connections from the throttle andconnections operable by engine suction, the joint eifect of which is toso control the contacts Ill and they cannot be closed except at suchtime as the engine is not running and after the throttle has been moveda predetermined distance toward its open position. Also the arrangementis such that the contacts cannot be opened during cranking of theengine, but will be held open at all times when the engine is operatingno matter how low the engine speed.

In order that the throttle in its movement may control the action ofthese contacts, an'arna 2" is secured to the throttle shalt by rivetingsuch arm to the cam I", or in any other suitable way. This arm 2 carriesa projecting lip or lug 2|! which is adapted to engage a rod 2 slidablein a bore in the wall of the main'housing II and having a reduced end2i. which is designed to contact with the spring arm III to which themovable contact Jill is secured. The construction oi the arm 2 and thelength of the rod 2" are such that when the throttle is in fully closedposition, as shownin Fig. 5, the rod occupies-a position far enough tothe right to hold the contact ill out of engagement with the fixedcontact I82 and in order for these contacts to close the throttle mustmove toward open position approximately 30 or more degrees.

The means which is controlled by engine suction for operating orcontrolling the switch com prising contacts I and "2 consists primarilyin a cam 2i2 which is rotatably mounted on a stud 2H secured in the wall01' the housing I'll. Projecting from the cam is an arm 2i! to which ispivotally connected a link 2Il, the other end of which is pivotallyconnected formed on an angle-shaped member 222 which is secured by arivet 224 to a diaphragm 228 the outer edge of which is secured betweena flange 22. projecting from a cup-shaped metal shell 2" and acooperating flange 222 formed on the housing I10. The edge of the shell2 is crimped or spun around the flange 222 as indicated in Pig. 4 of thedrawings to hold the diaphragm tightly between the flanges 22! and 232and form a leak-proof joint. Washers 234 and 2 are provided on oppositesides of the diaphragm and are held in assembled position II the rivet224 previously referred to. The washer 22. engages a spring 238 which isreceived between such washer and a shoulder 240 formed on the inside ofthe housing I10, said spring being adapted to hold the diaphragm in theposition shown in Figs. 2 and 5, when there is no suction effective onsuch diaphragm or when the suction which is effective thereon isinsufllcient to overcome the pressure of the spring.

Suction is communicated to the interior of the housing I10 through theopening 242 which registers with the cylinder it when the housing I'll'is assembled in position on the housing II, as shown in Fig. 3 of thedrawings.

It willbe apparent from consideration I Fig. that the spring arm I,which carries contact to an ear 22.v

scribed hereinafter.

I, has projecting therefrom a pin 2" and when the cam U2 is in suchposition that the highsurface thereon engages the pin 2", the contactsI" and "2 can never engage. The cam is moved to this podtion by theaction 0! the engine suction. as will be more fully explained later andwhen it is in such position, it is prevented from returning to theposition occupied in Pig. 5 so long as the pin 2" remains on the camsurface M2 by reason of a projecting toe or latching member 262 whichextends beyond the periphery position which releases the pin 2|! fromthe latch moved by the "2 and allows them 2 to be spring 238 to theposition shown drawings.

It is obvious from inl'igocithe inspection of Fig. 5 that the suctioneflect on the diaphragm 220 will move the link 2i. upwardly to rotatethe cam in a clockwise direction in order that the high surface may bebrought opposite the pin 2. It is, however necessary that such rotationshould not take place during the cranking of the engine because suchmovement of the cam would separate the contacts I and I82 and it it tookplace during cranking, the engine might not be started. are, therefore,provided to prevent the movement of the-cam in the manner describeduntil the engine suction is higher than is ever possible when operatingit at cranking The means for accomplishing this result comprises aspring detent which includes the spring pressed ball 2" which engages anorifice or depression 2" in a sleeve 2" which is secured to the cam M2and surrounds the stud 2. This sleeve is rotated with the cam and thespring held ball exerts suilicient pressure against its out to preventany rotary motion of the sleeve until the vacuum becomes higher than isever produced when the engine is rotated by the starting motor duringcranking. In fact the spring which holds the ball 2" in engagement withits seat in the sleeve 2" is of suiiicient strength to prevent anyrotary movement of the sleeve until a vacuum of 8 to 6 inches of mercuryis reached. The operation of this control switch during various engineoperating conditions will be more fully de- In view of the provision ofthis detent arrangement a very light diaphragm spring can be employedand so light a spring is used that a suction of y," of mercury is enoughto hold the switch open against the pressure of such spring. Thisprevents any possible closing of the switches as long as the engine isrunning under any possible operating condition.

In Fig. 7 of the drawings there is provided a diagrammatic view showingthe control switch. the connections from the accelerator pedal tooperate the throttle and the circuit of a preferred form of controldevice for the starting motor with whichthe control switch previouslydescribed is adapted to cooperate.

Referring to this figure, the starting motor is indicated at 2 and isprovided with a shaft is indicated at 264. This assembly includes asleeve 266 which is splined to the motor shaft pinion is adapted to bemoved to theright to its gear meshing position by a lever 212 pivotallysupported at 214 and the lower end of which engages a collar 216slidabie on the sleeve 266 and adapted to be held in the position shownby a coil spring 216 which is received between the collar and theclutch. When the lever 212 is moved in a counterclockwise direction ittends to move the entire driving assembly to the right sufilciently forthe pinion 216 to be meshed with the gear 264 and if the teeth of thepinion and gear are so positioned that the pinion can slide into gearwithout abutment of the teeth, the assembly will be so moved. If,however, the pinion teeth abut those of the .gear 264, the motion of thepinion to the right will be stopped but the lever will continue to movecompressing the spring 216.

At the upper end the lever is connected to the armature 266 of a magnetwhich must be energired to move the lever 212 and at the opposite endthe armature is provided with an enlarged head 282 which engages themovable contact 264 of the main starter switch which comprises inaddition fixed contacts 266 and 286 and is normally held open by thepressure of a spring 266. When the motion of the lever 212 as described,is effective to move the movable contact 264 into engagement withcontacts 266 and 266, the circuit of the starting motor is closed andthe shaft 262 thereof is rotated. This rotation of the shaft will movethe pinion 216 sufilciently to relieve the condition of tooth abutmentabove referred to and the spring 216 being collapsed and under pressurewill immediately force the pinion into engagement with the engine gear264.

The driving mechanism with the exception of the pinion shifting means,above described is not a portion of this invention in its detailedconstruction and is substantially what has been in public use for manyyears. While the magnet above referred to is not shown as of the samedetailed construction as what has been in use for some years on theBuick and other automo-' biles, the identical magnet which has been soused can be used in place of that shown in the drawings, the onlypurpose of this disclosure beeffected as has previously been stated, bythe action of a magnet having the armature 286. The magnet is providedwith a winding designated by the number 6I6 which is grounded throughthe connection 6I2 and through the wire 6 is connected to the bolt I64which secures the fixed contact I62 in position. The spring arm I84, asstated previously, is held in position by bolt I66 and to this bolt isconnected the wire 6I6 leading from the fixed contact 626 of theignition switch to the ignition system. The ignition switch is providedwith a movable contact 622 which is connected by wire 624 to the wire264 which has previously been described as extending to the battery.Obviously, when the contacts I66 and I62 are in engagement, current willA flow from the-battery through wire 264, wire 624,

ing illustrative, and is purely diagrammatic, the

details of the magnet being entirely unimportant so far as thisinvention is concerned.

The starting motor switch previously referred to is in circuit with abattery indicated at 262, the fixed contact 266 being connected by thelead 264 to the battery and is grounded through the connection 266. Theother contact 266 of the starting motor switch is connected by the wire266 to the commutator of the starting motor and is grounded through theconnection 666. Obviously, when thecontact 264 engages the contacts 266and 266 current will pass from the battery through the lead 264, theswitch comprising contacts above referred to, lead 266 to the startingmotor and through the connection 666 to ground from which it will passthrough connection 266'to the battery.

The closing of the above described switch is the ignition switch, wire6I6 and wire 6I6 to the movable contact I86. thence through the fixedcontact I62 when such switch is closed, to the bolt I64 and through thewire 6I4 to the winding 6I6 and thence to ground through the connection6I2. The closing of the ignition switch at any tim that the controlswitch comprising contacts I66 and I62 are closed, will, therefore,cause energization of the magnet and the motion of the armature 286 tothe left with the result that the pinion 216 is placed in drivingrelation with the gear 264 and the main starting motor switch comprisingcontacts 264, 266 and 286 is closed to complete the circuit of thestarting motor and cause the latter to operate. If either the ignitionswitch or the switch comprising contacts I66 and I62 be open, thecircuit of th starting motor cannot be closed and the switch comprisingcontacts I86 and I62 is always maintained in an open condition duringoperation of the en ine under its own power so that the starting motorcan never be rendered operative while the engine is running.

The generator charging circuit comprises the wire 264 which leads to thebattery and the wire 626 is connected therewith and extends to thegenerator 626 which is connected to ground through the connection 666.The usual cut-out relay is indicated at 662.

Operation So far as the operation of that portion of the unit whichcontrols the operation of th choke valve is concerned, the operation isnot greatly different from the choke operating mechanism used on the1937 Buick automobile, as the construction of the device hereindisclosed is not greatly difierent from that one, the essentials ofconstruction being the same and differing only in certain details. 7

If it be assumed that th engine is at rest and cold, with the throttlein closed position, the piston 16 is in its left hand position, as shownin Fig. 5, having been moved to that position by the cooperative actionof the spring 62 and the thermostat 66, which upon contraction moves thepiston to the left until its motion is stopped by engagement of theeccentric member I44 with its cooperating stop. With parts in thisposition, the choke valve is held closed by a force which variesinversely as the temperature. However, since the thermostat is held atone end by the spring 62 through the rack and segmental gear 16 and 14,the force exerted on such valve is no greater than the strength ofspring 62 in its extended position.

When the starting motor circuit is closed and purpose of rotating theengine in order to start it, said engine rotation creates suction or apartial vacuum in the intake manifold which is communicated to thecylinder to the right of piston 18. Due to the slow rotation of theengine at this time, however, the suction created is insuflicient toovercome the forces holding the piston to the left and if the enginefailed to start and the cranking period were prolonged, the engine wouldbe flooded unless means were provided to prevent such action. Such ameans is provided and is operable by the throttle to open the chokevalve during cranking if this be found necessary.

To accomplish this result, the throttle operates the cam I 30 to swingthe arm I downwardly so as to move arm II2 out of the path of spring I04to permit such spring to move to the right every time the throttle isopened. The spring I04 is stronger than spring 02, but exerts no forceto move piston 18 to the right when the parts are in the position shownin Fig. 2, because of the action of spring Hi. When the throttle opens,however, the pressure of the yoke on the opposite end of spring I04builds up the pressure of such spring as arm H2 is moved out of the paththereof, so that the pressure exerted thereby on the piston isconsiderably greater than the pressure of spring 82. This action willmove the rod 92, the piston 18, and in fact the whole assembly to theright as rapidly as th dash pot piston 00 will allow such action to takeplace. The retarding effect of the dash pot is, therefore, diminished asthe piston is moved to the right by reason of the tapered slot.Obviously, if flooding occurs in the event of prolonged cranking, allthat it is necessary to do is open the throttle which, through themedium of connections referred to, brings about a delayed openingmovement of the choke valve. The throttle may then be closed and thecranking operation continued until the engine starts.

With the present construction, the throttle must be moved to a. partlyopen position in order to start the engine for the reason that theswitch contacts I00 and I82 cannot engage until the throttle reachessuch position. There is, however. so much lost motion between the flangeI02 and the extension 90 of piston that the throttle can be moved to theposition necessary for the switch to close without the accompanyingmovement of the rod causing any opening of the choke valve.

When the engine starts to run under its own power, the suction effectiveon the piston 10 greatly increases, as well as the flow of air throughthe carburetor which is eifective on the unbalanced choke valve andthese forces are enough to overcome the pressure exerted by spring 02and the resistance of the dash pot to effect opening of the choke valveto a position determined by the suction and air flow. The action of thedash pot piston 98, however, retards the movement of the piston and thusprevents too rapid opening movement of the choke valve, or movement ofthe valve too far toward open position, in this way preventing theadmission of sufficient air to lean the mixture to an undesirable extentwhen the engine is operating under its own power during the warm upperiod.

If, after the engine is operating under its own power, the throttle beopened to accelerate the engine, the spring arm I04 and the dash potpiston 88 cooperate to provide a mixture of proper proportions duringthisperiod, but it is not desirable that the mixture be enriched 0 8 tcaus loading. Whenever the throttle is opened, the suction is reducedand the spring 02 tends to force the piston toward the left to effect aclosing movement of the choke valve. This closing movement of the chokevalve is controlled by the action of the dash pot and the spring arm I.

With the structure disclosed, if it be assumed that the engine isoperating at relatively low speed with but slightly open throttle, thepiston 10 stands somewhat to the right and the flange I02 may be aconsiderable distance from the extension 00 of piston I0. When thethrottle is opened the suction effective on the piston 10 immediatelydrops with the result that the spring 02 moves the piston toward theleft to effect closing of the choke valve. This movement will be rapiduntil the extension 90 strikes the flange I02 when it will be stopped bythe pressure of sprin arm I04. Also after the extension 00 engages theflange I02, the assembly including the piston will be moved back towardthe right as the throttle continues toward open position so that theclosing movement of the choke valve is only temporary. Thus the firstaction occurring upon opening movement of the throttle is a closing ofthe choke valve, followed by a second action which is an opening of thevalve due to the opening movement of the throttle which rotates cam I00,increasing the force of spring arm I04 and moving the piston 10 towardthe right against the pressure of spring 0!, to again move the chokevalve toward open position. This action permits the choke valve toassume a position where it is in a condition of balance, as determinedby the several springs operating thereon, the force of the thermostatand engine suction and prevents too great enrichment of the mixture uponacceleration.

It will also be understood that ii the throttle be opened foracceleration after it has reached a position where the surface I'l0b ofarm I10 is engaged by its cooperating roller there will be substantiallyno temporary closing oi the choke for acceleration purposes because theflange I02 will, under such conditions, have been moved into engagementwith extension of piston I0 and, therefore, a drop in suction followingthe opening of the throttle will not be effective to move the piston tothe left. Moreover, the further movement 01' the throttle toward openposition does not cause any considerable movement of the piston to theright, because of the nearly concentric shape 0b of the cam I30. Theabove described action is desirable because after a predeterminedthrottle opening is reached, temporary closing of the choke valve foracceleration purposes is substantially unnecessary.

It will be understood that the rate of movement of the piston 10 towardthe right, and consequently the rate of movement of the choke towardopen position will be determined by the movement of the dash pot piston98 toward the right, and it will also be apparent that the retardingeil'ect of such dash pot piston will be progressively reduced as saidpiston moves toward the right. It is not necessary to retard the openingmovement of the choke to as great a degree when said valve approachesits open position as when said valve is more nearly closed. This controlof the retarding eifect of the dash pot is brought about by the taperedslot previously described, which is formed in the wall of the dash potcylinder I00.

It w ll also be apparent that the dash pot conshift the driving pinioninto trols the movement to the left of piston 18 when the throttle isclosed from an open position as the return spring can return the partsno more rapidly than the dash pot permits.

Coming now to the operation of the control switch by means of which theaction of the starting motor is automatically regulated, it is obviousfrom consideration of the circuit diagram in Fig. 7, that the ignitionswitch and the switch comprising contacts I80 and I" must be closed andwhenever the ignition switch or the control switch is open, the startingmotor circuit is broken. When the engine is at rest, with the throttleclosed, the ignition switch is open and also the control is open becausethe closing of the throttle through the medium of the arm extending fromcam I30 moves the rod operated thereby so far to the right arm I84 sofar to the right that the control switch is open. Under these conditionsthe suction operated latch is in the position shown in Fig. 5.

To start the engine, assuming the throttle is closed and the ignitionturned off, it is necessary to close the ignition switch since thisswitch is in series in the starter control circuit and also to move thethrottle sufiloiently toward open position to permit the rod 208 to moveto the left enough to cause the control switch embodying contacts I80and I82 to close. This movement of the throttle is approximately 35 orthereabouts toward open position, which has been found desirable toprovide the desired quantity of mixture for starting purposes. Theclosing of the ignition switch and the closing of the control switch asdescribed, complete the control circuit with the result that the magnetis operated to engagement with flywheel gear and at the same time closethe main starting motor circuit, as previously described. The startermotor becomes operative then and will start the engine. As earlierpointed out, if the engine does not start promptly and the crankingperiod is prolonged without results, the operator should open thethrottle for the purpose of relieving flooding, as previously described.

When the engine starts to run under its own power; the action of theengine suction is such as to move the high surface of the control caminto engagement with the pin on spring arm I84 to open the controlswitch and break the starter circuit when the starter will becomeinoperative. As long as the engine suction remains relatively high, thecontrol cam will be :held in such position that the high surface isopposite the pin on that it pushes the spring] The spring detent whichcontrols the operation of the cam and the latch member is an importantfeature of this invention and makes it substantially impossible for thecontrol switch to be closed under any operating conditions which can bemet. It is obviously necessary that a device of this character must beconstructed so that the control switch cannot be opened during enginecranking or else the starter circuit would be broken and the enginewould not be started. Due to the fact that the throttle is generally inonly a partly open position during cranking, the suction may be higherwhen the engine is being turned by the tarting motor for the purpose ofstarting it than when it is operating under its own power with arelatively open throttle and heavy load. It has been found necessary toprovide a device which will not 1 open during cranking under a suctionof from cranking suction.

the spring arm I which is adapted to engage such cam surface and willhold the switch open. If, however, the engine is operating under heavyload with wide open throttle, the suction would drop and if means werenot provided to prevent such action, it might be possible to close thestarting motor circuit and cause serious damage to the starting system.This action is prevented by means of a latch member which is carried bythe cam and which engages the pin on the spring arm I84 to prevent areturn of the control com to its original position until the throttlehas been allowed to close so as to move the pin out of the path of thelatch member. Of course, if the throttle is closed, the suctionimmediately becomes high and the cam will not be permitted to move to aposition where the control switch can be closed because of the highsuction. If the throttle is again opened so that the suction drops, thelatch will become again effective.

3 inches of mercury, but will hold open during operation at a suctionmuch lower than that. The spring detent hereinbefore described, producesthese results and because of the engagement of the spring-held ball withthe cam member, the cam cannot be moved by engine suction until a vacuumof some 3% inches of mercury is reached, but after the ball isdisengaged from the recess in which it normally seats in the camchamber, the cam will be held by a suction of as little as a half aninch of mercury in its position where it will hold the switch open. Thisfeature of operation is of considerable importance because even whenoperating under a part throttle condition where the vacuum wouldnormally be high enough to hold th control switch open, under suchconditions the throttle might be in a position that the rod 208 does nothold the switch open, the operator might increase the load by steppingon the brake for some purpose, in which event the engine would slow downand the suction drop off to a point less than the However, with theconstruction shown there i= always under all conditions ufilcient vacuumto hold the control switch open.

While the embodiment of the present, invention as herein disclosed,constitutes a preferred form, it is to be understood that other formsmight be adopted, all coming within the scope of the claims whichfollow.

What is claimed is as follows:

1. In a starting apparatus for internal combustion engines having astarting motor, a current source, a circuit for connecting said motorand current source, a control switch for controlling said circuit, meansoperable by engine suction for preventing the closing of said switchwhile the engine is self-operative, resilient means engaging saidsuction operated means when the switch is closed and exertin a force toprevent operation of said suction operated means, which is appreciablygreater than the force exerted on said means by engine suction duringrotation of the engine by the starting motor but less than the forceexerted by engine suction when the engine becomes self -operative.

2. In a starting apparatus f0! internal combustion engines having acurrent source, a starting motor operable by current from said sourceand a circuit for connecting said starting motor with the currentsource, aswitch for controlling said circuit, means for operating saidswitch, a control member movable to two positions in one of which itprevents closing of th switch and in the other of which it permits saidswitch to be closed to cause operation of the starting motor,

means operable by the engine when it becomes self-operative to mov saidcontrol member to a position where it prevents closing of the switch,and means engaging said control member for preventing such movement ofsaid control memher while the engine is being operated by the startingmotor, said last named means being ineffective to prevent such movementof said control member whenever the engine begins to operate under itown poweri 3. In a starting apparatus for internal cmbustion engineshaving a current source, a starting motor operable by current from saidsource and a circuit for connecting said starting motor with the currentsource, a switch for controlling said circuit, means for operating saidswitch, a control member movable to two position in one of which itprevents closing of the switch and in the other of which it permits saidswitch to be closed. to cause operation of the starting motor, meansoperable by engine suction when the engine begins to run under its ownpower to move said control member to a position where it preventsclosing of the switch, and means engaging said control member forpreventing such movement of the control member while the engine is beingoperated by the starting motor, said engaging means being ineiiective toprevent movement of the control member whenever the engine becomes selfoperative.

4. In a starting apparatus for internal combustion engines having acurrent source, a start ing motor operable by current from said sourceand a circuit for connecting the starting motor with said currentsource, a switch for controlling said circuit and provided with aplurality of contact members, a control member movable by engine suctionto a position to prevent closing of the switch when the engine becomesselfoperative, means engaging said control member to hold it in positionto prevent closing 0!, the switch as long as the engine isself-operative and manually operable means eilfeetive when moved in onedirection to disengage said last named means from the control member topermit the latter to return to its normal inoperative position when theengine is not running in order to permit closing of the switch andeffective when moved in the other direction to cause said switch to beclosed in order to render the starting motor operative.

5. In a starting apparatus for inte al ombustion engines having acurrent source, i ing motor operable by current from said source and acircuit for connecting the star motor with said current source, a switchfor controlling said circuit and provided with a plurality of contactmembers, a control member movabie by engine suction to a position toprevent closing of the switch when the engine becomes operative, a latchforv engaging the surface of the control member when said member hasbeen moved by engine suction to the position it occupies when the switchis held open, to maintain said control member in such position as longas the engine is self operative, and manual means for disengaging thelatch from the control mem-- her to permit the control member to returnto its normal inoperative position when the engine becomes inoperative,so that the switch may be closed to start said engine.

6. In a starting apparatus for internal cornbustion engines havin acurrent source, a starting motor operable by current from said sourceand a circuit for connecting the starting motor with said currentsource, a switch for controlling said circuit and provided with aplurality of contact members, a control member movable by engine suctionand having a cam formed thereon with one abrupt face, said controlmember being moved to a position where the cam prevents closing of theswitch, and a latch member for engaging the abrupt face of the cam tohold the control member in position to prevent closing of the switch aslong as the engine is self-operative, and manual means for effectingrelease of the cam from the latch to permit return of the control memberto normal position.

7. In a starting apparatus for internal combustion engines having acurrent source, a starting motor operable by current from said sourceand a circuit for connectin the starting motor with said current source,a switch for controlling said circuit and provided with a plurality 0!contact members, a control member movable by engine suction to aposition to prevent closing of the switch when the engine becomesself-opentive, means engaging said control member and effective toprevent movement of said control member by suction during operation ofthe engine by the starting motor, but ineilective to prevent movement ofsaid control member by auction when the engine becomes self-operative,and a second means eflective to hold the control memto which it is movedby engine suction as long as the engine is self-operative, to preventany possible closing of the starting motor circuit while the engine isrunning under its own power.

8. In a starting apparatus for internal combustion engines havin a,current source, a starting motor operable by current from said sourceand a circuit for connecting the starting motor with said currentsource, a, switch for controlling said circuit and provided with aplurality of contact members, a control member movable by engine suctionto a position to prevent closing of the switch when the engine becomesself-operative, means engaging said control member and effective toprevent movement of said control member by suction during operation ofthe enmotor, but inerfective to presaid control member by sucticn whenthe engine becomes self-operative, and a latch adapted to directlyengage the control member to hold said member in the position to whichit is moved by engine suction as long as the engine is self-operative toprevent any possible closin of the starting motor circuit while theengine is running under its own power.

9, In a, starting apparatus for internal coming motor circuit while theengine is running under its own power, and manual means for disablingsaid last named means so as to permit the control member to return tothe position from which it is moved by engine suction.

10. In a starting apparatus for internal combustion engines having acurrent source, a starting motor operable by current from said sourceand a circuit for connecting the starting motor with said currentsource, a switch for controlling said circuit and provided with aplurality of 0011- tact members, a control member movable by enginesuction to a position to prevent closing of the switch when the enginebecomes selfoperativ means engaging said control member and effective toprevent movement of said control member by suction during operation ofthe engine by the starting motor, but ineffective to prevent movement ofsaid control member by suction when the engine becomes self-operative, alatch adapted to directly engage the control member to hold said memberin the position to which it is moved by engine suction as long as theengine is self-operative to prevent any possible closing of the startingmotor circuit while the engine is running under its own power, andmanual means for disengaging the latch so as to permit the controlmember to return to the position from which it is moved by enginesuction.

11. In a starting apparatus for internal combustion engines having acurrent source, a starting motor operable by current from said sourceand a circuit for connecting the starting motor with said currentsource, a switch for controlling said circuit and provided with fixedand movable contact members, a control member engaging said movablecontact and movable by engine suction to a position to prevent movementof the contact to a position to close the switch when the engine becomesself-operative, and means whereby the movable contact is effective tohold the control member in position to prevent closing of the switch aslong as the engine is self-operative. v

12. In a starting apparatus for internal combustion engines having acurrent source, a starting motor operable by current from said sourceand a circuit for connecting the starting motor with said currentsource, a switch for controlling said circuit and provided with fixedand movable contact members, a control member engaging said movablecontact and movable by engine suction to a position to prevent movementof the contact to a position to close the switch when the engine becomesself-operative, means whereby the movable contact is efl'ective to holdthe control member in position to prevent closing of the switch as longas the engine is self-operative and manual means eiIective to releasethe control member from said movable contact in order to permit saidcontrol member to return to the position from which it is moved byengine suction.

13. In a starting apparatus for internal combustion engines having acurrent source, a starting motor operable by current from said sourceand a circuit for connecting the starting motor with said currentsource, a switch for control ing said circuit and provided with fixedand movable contact members, a control member movable by engine suctionto a position to prevent closing of the switch when the engine becomessolioperative, means engaging said control member bustion engines havinga current source, I

in position to prevent closing of the long asthe engine isself-operative.

14. In a starting apparatus for inte nal core ta i ing motor operable bycurrent from said 5 and a circuit for connecting the starting rm withsaid current source, a switch for cont ling said circuit and providedwith and movable contact members, a control member able by enginesuction to a position to prevent closing of the switch when the enginebecomes self-operative, means engaging said control member and effectiveto prevent movement thereof by suction during operation of the engine bythe starting motor, means whereby'the movable contact is eifective tohold the control member in position to prevent closing of the switch aslong as the engine is self-operative, and manual means for rendering themovable contact inefiective to hold the control member in position toprevent closing or the switch in order to permit the control member toreturn to the position from which it was moved by engine suction.

15. In a starting apparatus for internal combustion engines having acurrent source, a start ing motor operable by current from said sourceand a circuit for connecting the starting motor with said currentsource, a switch for controlling said circuit and provided with fixedand movable contact members, a control member engaging said movablecontact and movable by engine suction to a position to prevent movementof the movable contact to a position to close the switch when the enginebecomes self-operative, said control member having a surface thereonadapted to be engaged by said movable contact when the control member ismoved to a position to hold the switch open so as to hold the controlmemher in such position, and another means engag ging the control memberand eiIective to prevent movement of said control member when the engineis operated by the starting motor.

16. In a starting apparatus for internal combustion engines having acurrent source, a starting motor operable by current from said sourceand a circuit for connecting the starting motor with said currentsource, a switch for controlling said circuit and provided with fixedand movable contact members, a control member engaging said movablecontact and movable by engine suction to a position to prevent movementof the movable contact to a position to close the switch when the enginebecomes self-operative, said control member having a surface thereonadapted to be engaged by said movable contact when the control member ismoved to a position to hold the switch open so as to hold the controlmember in such position, another means engaging the control member andeffective to prevent movement of said control member when the engine isoperated by the starting motor, and manual means operable to disengagethe movable contact from said surface so as to permit the control memberto return to the position from which it is moved by engine suction.

CLARENCE H. JORGENBEN.

LAWRENCE C. DERMOND'

